I know there is a way to add/modify fields you fill in when you register to my site because I already have found it. Now is my problem than I don't know how to remove fields like "zodiac", "points" and "Chinese zodiac". How can I do that?

To change the fields go to :Admin Panel > Users & Groups > Users > Profilesand edit the fields there and change the necessary fields. Those fields are the ones that must be filled at the registration and you can change those field there. The zodiac and Chinese zodiac and points can be hidden from profile and messages by ticking and un-tick the profile and message fields. That way if they are ticked then they will show wherever you want and not show when its not ticked.